Problem> There is a binary file (I’ll use an Excel file) that you want to embed in any C# assembly. Later on, at runtime, you want to extract the file from the EXE and continue working on it. In this post, I will share the code and describe how you can do that. You can use the same technique for any other kind of binary file as well.

Solution> First up, the reason why you may choose to embed a resource directly into your EXE is to ensure that no one tampers your file on which your code is based. This post doesn’t talk about handling an Excel file. It mainly focuses on two parts… embedding any file directly in your EXE, and then extract it at runtime and execute it.

    Create a new Windows Forms Project
    Add an Existing file (I’ve added a file called File.xlsx) in the project
    Right click on File.xlsx and select Properties
    Change the Build Action –> Embedded Resource

    Switch to the form where you want to extract and use this resource
    Add the following to the top of the code behind…

using System.Reflection;
using System.IO;

     Add the following methods and call ExtractFromAssembly method.

private void ExtractFromAssembly()
{
    string strPath = Application.LocalUserAppDataPath + "\\OutputFile.xlsx";
    if (File.Exists(strPath)) File.Delete(strPath);
    Assembly assembly = Assembly.GetExecutingAssembly();
    //In the next line you should provide NameSpace.FileName.Extension that you have embedded
    var input = assembly.GetManifestResourceStream("Sample.File.xlsx");
    var output = File.Open(strPath, FileMode.CreateNew);
    CopyStream(input, output);
    input.Dispose();
    output.Dispose();
    System.Diagnostics.Process.Start(strPath);
}

private void CopyStream(Stream input, Stream output)
{
    byte[] buffer = new byte[32768];
    while (true)
    {
        int read = input.Read(buffer, 0, buffer.Length);
        if (read <= 0)
            return;
        output.Write(buffer, 0, read);
    }
}

     Yes, that’s pretty much it!

Hope this helps,
Rahul

Quote of the day:
I'm an idealist. I don't know where I'm going, but I'm on my way. - Carl Sandburg